goonscape/network/network.go

package network

import (
	"bufio"
	"encoding/binary"
	"fmt"
	"io"
	"log"
	"net"
	"sync"
	"time"

	"gitea.boner.be/bdnugget/goonscape/types"
	pb "gitea.boner.be/bdnugget/goonserver/actions"
	rl "github.com/gen2brain/raylib-go/raylib"
	"google.golang.org/protobuf/proto"
)

const protoVersion = 1

var serverAddr = "boner.be:6969"

func SetServerAddr(addr string) {
	serverAddr = addr
}

func ConnectToServer(username, password string, isRegistering bool) (net.Conn, int32, error) {
	conn, err := net.Dial("tcp", serverAddr)
	if err != nil {
		log.Printf("Failed to dial server: %v", err)
		return nil, 0, err
	}

	log.Println("Connected to server. Authenticating...")

	// Send auth message
	authAction := &pb.Action{
		Type:     pb.Action_LOGIN,
		Username: username,
		Password: password,
	}
	if isRegistering {
		authAction.Type = pb.Action_REGISTER
	}

	authBatch := &pb.ActionBatch{
		Actions:         []*pb.Action{authAction},
		ProtocolVersion: protoVersion,
	}

	if err := writeMessage(conn, authBatch); err != nil {
		conn.Close()
		return nil, 0, fmt.Errorf("failed to send auth: %v", err)
	}

	// Read server response
	reader := bufio.NewReader(conn)
	lengthBuf := make([]byte, 4)
	if _, err := io.ReadFull(reader, lengthBuf); err != nil {
		conn.Close()
		return nil, 0, fmt.Errorf("failed to read auth response: %v", err)
	}
	messageLength := binary.BigEndian.Uint32(lengthBuf)

	messageBuf := make([]byte, messageLength)
	if _, err := io.ReadFull(reader, messageBuf); err != nil {
		conn.Close()
		return nil, 0, fmt.Errorf("failed to read auth response body: %v", err)
	}

	var response pb.ServerMessage
	if err := proto.Unmarshal(messageBuf, &response); err != nil {
		conn.Close()
		return nil, 0, fmt.Errorf("failed to unmarshal auth response: %v", err)
	}

	if response.ProtocolVersion > protoVersion {
		conn.Close()
		return nil, 0, fmt.Errorf("server requires newer protocol version (server: %d, client: %d)",
			response.ProtocolVersion, protoVersion)
	}

	if !response.AuthSuccess {
		conn.Close()
		return nil, 0, fmt.Errorf(response.ErrorMessage)
	}

	playerID := response.GetPlayerId()
	log.Printf("Successfully authenticated with player ID: %d", playerID)
	return conn, playerID, nil
}

func HandleServerCommunication(conn net.Conn, playerID int32, player *types.Player, otherPlayers map[int32]*types.Player, quitChan <-chan struct{}) {
	reader := bufio.NewReader(conn)
	defer func() {
		if r := recover(); r != nil {
			log.Printf("Recovered from panic in HandleServerCommunication: %v", r)
		}
		conn.Close()
		if player.QuitDone != nil {
			close(player.QuitDone)
		}
	}()

	actionTicker := time.NewTicker(types.ClientTickRate)
	defer actionTicker.Stop()

	// Create error channel for goroutine communication
	errChan := make(chan error, 1)
	done := make(chan struct{})

	// Start message sending goroutine
	go func() {
		defer func() {
			if r := recover(); r != nil {
				log.Printf("Recovered from panic in message sender: %v", r)
				errChan <- fmt.Errorf("message sender panic: %v", r)
			}
		}()

		for {
			select {
			case <-quitChan:
				// Send disconnect message to server
				disconnectMsg := &pb.ActionBatch{
					PlayerId: playerID,
					Actions: []*pb.Action{{
						Type:     pb.Action_DISCONNECT,
						PlayerId: playerID,
					}},
				}
				writeMessage(conn, disconnectMsg)
				done <- struct{}{}
				return
			case <-done:
				return
			case <-actionTicker.C:
				player.Lock()
				if len(player.ActionQueue) > 0 {
					actions := make([]*pb.Action, len(player.ActionQueue))
					copy(actions, player.ActionQueue)
					batch := &pb.ActionBatch{
						PlayerId: playerID,
						Actions:  actions,
						Tick:     player.CurrentTick,
					}
					player.ActionQueue = player.ActionQueue[:0]
					player.Unlock()

					if err := writeMessage(conn, batch); err != nil {
						errChan <- err
						return
					}
				} else {
					player.Unlock()
				}
			}
		}
	}()

	// Main message receiving loop
	go func() {
		defer func() {
			if r := recover(); r != nil {
				log.Printf("Recovered from panic in message receiver: %v", r)
				errChan <- fmt.Errorf("message receiver panic: %v", r)
			}
		}()

		for {
			select {
			case <-quitChan:
				return
			default:
				lengthBuf := make([]byte, 4)
				if _, err := io.ReadFull(reader, lengthBuf); err != nil {
					if err != io.EOF {
						errChan <- fmt.Errorf("failed to read message length: %v", err)
					}
					return
				}
				messageLength := binary.BigEndian.Uint32(lengthBuf)

				messageBuf := make([]byte, messageLength)
				if _, err := io.ReadFull(reader, messageBuf); err != nil {
					log.Printf("Failed to read message body: %v", err)
					return
				}

				var serverMessage pb.ServerMessage
				if err := proto.Unmarshal(messageBuf, &serverMessage); err != nil {
					log.Printf("Failed to unmarshal server message: %v", err)
					continue
				}

				player.Lock()
				player.CurrentTick = serverMessage.CurrentTick

				tickDiff := serverMessage.CurrentTick - player.CurrentTick
				if tickDiff > types.MaxTickDesync {
					for _, state := range serverMessage.Players {
						if state.PlayerId == playerID {
							player.ForceResync(state)
							break
						}
					}
				}
				player.Unlock()

				for _, state := range serverMessage.Players {
					if state.PlayerId == playerID {
						player.Lock()
						// Update initial position if not set
						if player.PosActual.X == 0 && player.PosActual.Z == 0 {
							player.PosActual = rl.Vector3{
								X: float32(state.X * types.TileSize),
								Y: 0,
								Z: float32(state.Y * types.TileSize),
							}
							player.PosTile = types.Tile{X: int(state.X), Y: int(state.Y)}
						}
						player.Unlock()
						continue
					}

					if otherPlayer, exists := otherPlayers[state.PlayerId]; exists {
						otherPlayer.UpdatePosition(state, types.ServerTickRate)
					} else {
						otherPlayers[state.PlayerId] = types.NewPlayer(state)
					}
				}

				// Remove players that are no longer in the server state
				for id := range otherPlayers {
					if id != playerID {
						delete(otherPlayers, id)
					}
				}

				if handler, ok := player.UserData.(types.ChatMessageHandler); ok && len(serverMessage.ChatMessages) > 0 {
					handler.HandleServerMessages(serverMessage.ChatMessages)
				}
			}
		}
	}()

	// Wait for error or quit signal
	select {
	case <-quitChan:
		// Send disconnect message
		disconnectMsg := &pb.ActionBatch{
			PlayerId: playerID,
			Actions: []*pb.Action{{
				Type:     pb.Action_DISCONNECT,
				PlayerId: playerID,
			}},
		}
		writeMessage(conn, disconnectMsg)
	case err := <-errChan:
		log.Printf("Network error: %v", err)
	}
}

// Helper function to write length-prefixed messages
func writeMessage(conn net.Conn, msg proto.Message) error {
	data, err := proto.Marshal(msg)
	if err != nil {
		return err
	}

	// Write length prefix
	lengthBuf := make([]byte, 4)
	binary.BigEndian.PutUint32(lengthBuf, uint32(len(data)))
	if _, err := conn.Write(lengthBuf); err != nil {
		return err
	}

	// Write message body
	_, err = conn.Write(data)
	return err
}

type Connection struct {
	conn      net.Conn
	playerID  int32
	quitChan  chan struct{}
	quitDone  chan struct{}
	closeOnce sync.Once
}

func NewConnection(username, password string, isRegistering bool) (*Connection, error) {
	conn, playerID, err := ConnectToServer(username, password, isRegistering)
	if err != nil {
		return nil, err
	}
	return &Connection{
		conn:     conn,
		playerID: playerID,
		quitChan: make(chan struct{}),
		quitDone: make(chan struct{}),
	}, nil
}

func (c *Connection) Close() {
	c.closeOnce.Do(func() {
		close(c.quitChan)
		// Wait with timeout for network cleanup
		select {
		case <-c.quitDone:
			// Clean shutdown completed
		case <-time.After(500 * time.Millisecond):
			log.Println("Network cleanup timed out")
		}
		c.conn.Close()
	})
}

func (c *Connection) PlayerID() int32 {
	return c.playerID
}

func (c *Connection) Start(player *types.Player, otherPlayers map[int32]*types.Player) {
	go HandleServerCommunication(c.conn, c.playerID, player, otherPlayers, c.quitChan)
}

func (c *Connection) QuitChan() <-chan struct{} {
	return c.quitChan
}